The declaration of the historic centers of the cities of Quito and Cuenca, in the Republic of Ecuador, as Cultural Heritage of Humanity by UNESCO, in 1978 and 1991, respectively, has presented various vicissitudes and consequences over time: from a renewed sense of pride and belonging on the part of the local population and its rulers; the irruption of cultural tourism and the changes of use of the spaces involved in said UNESCO declaration, with its positive and negative impacts from the economic, social and environmental point of view, depending on the case, to a series of problems such as the accelerated loss of inhabitants of these historic centers and the resulting gentrification processes, traffic congestion and pedestrian circulation, environmental pollution or changes in the traditional use of heritage buildings. Through documentary and bibliographic review and the use of technological tools for qualitative research such as Atlas.ti, this work has proceeded to describe both the characteristics of both historic centers and to identify the various problems that affect both urban spaces. The results, with this computer application, have made it possible to discover the main existing difficulties, both in Quito and in Cuenca, to overcome these problems and contribute to the development of cultural tourism in both cities from a comprehensive sustainability perspective.